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pro vyhledávání: '"Thomas A. Laakso"'
Autor:
Thomas A. Laakso, Daniel P. Schrag
Publikováno v:
Isotopic Constraints on Earth System Processes. :203-216
Autor:
Thomas A. Laakso, Daniel P. Schrag
Publikováno v:
Earth and Planetary Science Letters. 522:48-54
Biological methane production occurs in anoxic terrestrial wetlands and in sulfate depleted marine sediments. It has been suggested that methanogens may have flourished in the anoxic and sulfate-poor environments of the Precambrian ocean, generating
Autor:
Thomas A. Laakso, Daniel P. Schrag
Publikováno v:
Geobiology. 17:161-171
The riverine supply of the globally limiting nutrient, phosphorus, to the ocean accounts for only a few percent of nutrient supply to photosynthetic organisms in surface waters. Recycling of marine organic matter by heterotrophic organisms provides a
Publikováno v:
Proc Natl Acad Sci U S A
Changes in the geological sulfur cycle are inferred from the sulfur isotopic composition of marine barite. The structure of the (34)S/(32)S record from the Mesozoic to present, which includes ∼50- and 100-Ma stepwise increases, has been interpreted
Publikováno v:
Proceedings of the National Academy of Sciences of the United States of America
Significance The evolution of macroscopic animals in the latest Proterozoic Eon is associated with many changes in the geochemical environment, but the sequence of cause and effect remains a topic of intense research and debate. In this study, we use
Autor:
David T. Johnston, Francis A. Macdonald, Thomas A. Laakso, Daniel P. Schrag, Frasier L. Liljestrand
Publikováno v:
GeobiologyREFERENCES. 18(4)
Throughout most of the sedimentary record, the marine carbon cycle is interpreted as being in isotopic steady state. This is most commonly inferred via isotopic reconstructions, where two export fluxes (organic carbon and carbonate) are offset by a c
Autor:
Thomas A. Laakso, Daniel P. Schrag
Publikováno v:
Geological Society of America Abstracts with Programs.
Autor:
Daniel P. Schrag, Thomas A. Laakso
Publikováno v:
Geological Society of America Abstracts with Programs.
Autor:
Thomas A. Laakso, Daniel P. Schrag
Publikováno v:
Earth and Planetary Science Letters. 388:81-91
Many studies suggest that oxygen has remained near modern levels throughout the Phanerozoic, but was much less abundant from the “Great Oxygenation Event” around 2.4 Ga until the late Neoproterozoic around 600 Ma ( Kump, 2008 ). Using a simple mo
Autor:
Thomas A. Laakso
Publikováno v:
Nature Geoscience. 11:6-7